Recent advances in improving utilization efficiency of precious metal catalysts for hydrogen generation from hydrolysis of ammonia borane

Hydrogen is considered to be a crucial carrier for future energy supply. Effective and safe storage and release of hydrogen are prerequisites for the future hydrogen economy. Ammonia borane (AB) has received extensive attention and research over the last decade as a hydrogen storage and release material. Precious metal catalysts, including Pd, Ru, Pt, and Rh, are recognized as the state-of-art catalysts for hydrogen production from AB. However, their high cost and low crustal abundance restrict their widespread application. Efforts have been made to improve their utilization efficiency through developing cost-effective catalysts with high performances, and remarkable advances have been achieved. The root of the activity and stability of catalysts lies in the coupling between precious metal active centers and their surrounding components. Herein, we first summarize the coupling effects, such as electronic effect, strain effect, metal-support interactions (MSIs) effect and synergistic effect. Then effective strategies, including alloying 3d transition metals, doping 3d transition metal oxides, doping non-metals in supports, single-atom strategy, vacancy creating and morphology control, are highlighted. The relationships among catalytic activity, composition, structure and morphology are systematically discussed. Finally, the research directions and challenges for the developing of precious metal catalysts are featured.